Minimization of the reactive current in nonsinusoidal situations with a reactive compensator usually requires some information concerning the frequency parameters of the circuit. Particularly, for the optimal LC compensator design, the rms values of the source voltage harmonics Un, and the load susceptances Bn, have to be measured. It is shown in this paper, however, that the optimal capacitance of such an LC compensator can also be determined without this information, but in the time-domain. This can be done by an iterative procedure which requires that the scalar product of the load current io and the derivative of the capacitor voltage [FORMULLA OMITTED], and their rms values, ∥ io ∥ and ∥ [FORMULLA OMITTED] ∥, be measured. © 1990 IEEE